The latest QCAD release 3.4.7 brings with it performance improvements when selecting many entities, which it certainly does. My test case attached is a master site plan and previously when using QCAD to open this and work with it proved somewhat unsuccessful, and understandably so, it is a heavy drawing - meaning a lot of entities to cope with.The drawing now opens and I can select what I need to and work with it, general zooming, panning operations are now much improved, thanks.

The only thing I notice now with this drawing (no problems with other drawing files) is that using Autozoom doesn't work, is there a reason for this?

QCAD does not allow zoom factors under a certain limit to prevent overflows. However, this would be required for drawings with such extreme extents.

I've made this check more tolerant for future releases.The check can also be completely disabled in the next release by unchecking the option Edit > Application Preferences > Graphics View > Navigation > Limit zoom and scroll to prevent overflows.

andrew wrote:QCAD does not allow zoom factors under a certain limit to prevent overflows. However, this would be required for drawings with such extreme extents.

I've made this check more tolerant for future releases.The check can also be completely disabled in the next release by unchecking the option Edit > Application Preferences > Graphics View > Navigation > Limit zoom and scroll to prevent overflows.

Smashing, thanks Andrew, this will help tremendously, thank you vey much

Husky wrote:Question: Is it right that you work on something like this in millimeter? Just curios ...

Huh, yes I suppose this may seem odd, the file was sent to me from a student, they can work in whatever unit size they wish too, doesn't really bother me, so long as I can open the file and edit/adjust etc. for laser cutting specific details. Makes you think though ... do they really know what they are doing most of the time ... probably they do (I hope they do ).

For the best support please state your operating system, QCAD version and add any supporting DXF/DWG files, screenshots etc...

Edit last post of me - important!!!After playing around I figured out that QCAD is picky in which order I change the Drawing Preferences for DIM and Drawing Units.Normally my defaults are Inch bla bla bla for new drawings. If I paste the Clipboard content into this "inch" new drawing and change then the DIM and Unit values to mm everything works nicely with the auto zoom.But, if I create a new drawing - adjust the DIM and Drawing units FIRST and paste then the clipboard content into it - it doesn't works with the auto zoom function ....

Yeah, thanks Husky for the tip, increasing the unit size for this particular drawing helps (from MM to CM) and works. I guess Andrews fix for the next release will be the ideal situation but for now this workaround works fine, thanks again.

For the best support please state your operating system, QCAD version and add any supporting DXF/DWG files, screenshots etc...

Husky wrote:But, if I create a new drawing - adjust the DIM and Drawing units FIRST and paste then the clipboard content into it - it doesn't works with the auto zoom function ....

This makes sense. QCAD converts the pasted drawing to the unit of the drawing you paste to. So you are essentially converting the drawing to another unit, which results in different (smaller) coordinates, which solves the overflow problem since coordinate values are not that large anymore.

If you adjust the unit after pasting, QCAD does not convert your drawing to the new unit since it assumes you just wanted to correct the unit of the drawing. What used to be 1 old unit is now 1 new unit.

andrew wrote:QCAD converts the pasted drawing to the unit of the drawing you paste to. So you are essentially converting the drawing to another unit, which results in different (smaller) coordinates, which solves the overflow problem since coordinate values are not that large anymore.